Claims
- 1. In a process for preparing a sulfur-containing fossil fuel for combustion: forming a basic and distributed precursor by subjecting the fuel for combustion to an oxidative treatment at approximately ambient temperature; and subjecting the oxidant-treated fuel to a basic aqueous solution of a compound of an alkali metal or an alkaline earth metal without substantially removing the sulfur from the fuel, whereby, upon combustion of the fuel, a major portion of the sulfur in the fuel will be trapped in the reaction with the precursor and appear in the resulting ash as a sulfate.
- 2. In a process as set forth in claim 1, wherein is included the step of burning the fuel to extract the heating value therefrom.
- 3. In a process as set forth in claim 1, wherein said fuel is coal.
- 4. In a process as set forth in claim 1, wherein said fuel is lignite.
- 5. In a process as set forth in claim 1, wherein said fuel is peat.
- 6. In a process as set forth in claim 1, wherein said fuel has an organic sulfur content and an inorganic sulfur content.
- 7. In a process as set forth in claim 1, wherein said step of subjecting the fuel to an oxidative treatment includes slurrying the fuel in a suspending liquid containing an oxidizing agent and retaining the fuel in said slurry for a sufficient time period to allow for the introduction of a sufficient amount of anionic oxygen which binds to a sufficient amount of ions of metals from the alkali metal or alkaline earth metal to trap the sulfur in the fuel upon combustion.
- 8. In a process as set forth in claim 7, wherein said fuel is coal.
- 9. In a process as set forth in claim 7, wherein said fuel is lignite.
- 10. In a process as set forth in claim 7, wherein said fuel is peat.
- 11. In a process as set forth in claim 7, wherein the oxidizing agent includes NO.sub.2.
- 12. In a process as set forth in claim 7, wherein the suspending liquid includes CCl.sub.4.
- 13. In a process as set forth in claim 12, wherein the liquid phase includes CCl.sub.4 that is 1.1 formal in NO.sub.2.
- 14. In a process as set forth in claim 7, wherein the suspending liquid includes water.
- 15. In a process as set forth in claim 7, wherein is included the step of separating the fuel from said suspending liquid after said time-interval and before subjecting the fuel to said basic aqueous solution.
- 16. In a process as set forth in claim 1, wherein said step of subjecting the fuel to an oxidative treatment includes mixing the fuel with a fluid containing an oxidizing agent, and sustaining the mixture for a sufficient time period to allow for the introduction of a sufficient amount of anionic oxygen which binds to a sufficient amount of ions of metals from the alkali metal or alkaline earth metal to trap the sulfur in the fuel upon combustion.
- 17. In a process as set forth in claim 16, wherein said fuel is coal.
- 18. In a process as set forth in claim 16, wherein said fuel is lignite.
- 19. In a process as set forth in claim 16, wherein said fuel is peat.
- 20. In a process as set forth in claim 1, wherein the fuel is subjected to said oxidative treatment for a time interval in the range of 5 minutes to 180 minutes.
- 21. In a process as set forth in claim 1, wherein said basic aqueous solution includes a 0.1 M Na.sub.2 CO.sub.3 solution.
- 22. In a process as set forth in claim 1, wherein said step of subjecting the fuel to an oxidative treatment includes forming an ion-exchange structure in the hydrogen-ion mode.
- 23. In a process as set forth in claim 22, wherein the fuel is coal.
- 24. In a process as set forth in claim 22, wherein the fuel is lignite.
- 25. In a process as set forth in claim 22, wherein the fuel is peat.
- 26. A process of preparing a sulfur-containing fossil fuel for combustion comprising: forming a basic and distributed precursor by subjecting the fuel to an oxidizing agent for a first time-interval to provide an oxidative treatment of the fuel; and thereafter mixing the fuel with a basic aqueous solution of a compound of a metal selected from the group including alkali metals and alkaline earth metals; maintaining the system for a second-time-interval without substantially removing the sulfur from the fuel and without substantially reducing the heating value of the fuel; and removing the fuel from said system, whereby a major portion of the sulfur in the fuel, when the fuel is burned, will be trapped as a sulfate in the ash.
- 27. A process as set forth in claim 26, wherein said oxidizing agent includes NO.sub.2.
- 28. A process as set forth in claim 26, wherein said metal includes sodium.
- 29. A process as set forth in claim 26, wherein said compound includes Na.sub.2 CO.sub.3.
- 30. A process as set forth in claim 26, wherein the step of subjecting the fuel to said oxidizing agent is performed at approximately ambient temperature.
- 31. A process as set forth in claim 26, wherein the step of subjecting the fuel to said oxidizing agent is performed at approximately ambient temperature and atmospheric pressure.
- 32. A process as set forth in claim 26, wherein the solution is at approximately ambient temperature during said second time-interval.
- 33. A process as set forth in claim 26, wherein the solution is at approximately ambient temperature and atmospheric pressure during said second time-interval.
- 34. A process as set forth in claim 26, wherein the step of subjecting the fuel to an oxidizing agent includes direction NO.sub.2 gas into contact with the fuel.
- 35. A process as set forth in claim 26, wherein the step of subjecting the fuel to an oxidizing agent includes directing the fuel into a fluid containing said oxidizing agent.
- 36. A process as set forth in claim 35, wherein said oxidizing agent includes NO.sub.2.
- 37. A process as set forth in claim 35, wherein is included the step of separating the fuel from the fluid after said first time-interval and before said directing step.
- 38. A process as set forth in claim 26, wherein the first time-interval is in the range of 5 to 180 minutes.
- 39. A process as set forth in claim 26, wherein the second time-interval is in the range of 5 minutes to 3 hours.
- 40. A process as set forth in claim 26, wherein the fuel has an organic sulfur content and an inorganic sulfur content.
- 41. A process as set forth in claim 26, wherein the fuel is coal.
- 42. A process as set forth in claim 26, wherein the fuel is lignite.
- 43. A process as set forth in claim 26, wherein the fuel is peat.
- 44. A process as set forth in claim 26, wherein the step of subjecting the fuel to an oxidizing agent includes forming an ion-exchange structure in the hydrogen-ion mode.
- 45. In a process as set forth in claim 44, wherein said fuel is coal.
- 46. In a process as set forth in claim 44, wherein said fuel is lignite.
- 47. In a process as set forth in claim 44, wherein said fuel is peat.
- 48. In a process as set forth in claim 26, wherein is included the step of removing the inorganic sulfur from the fuel before said step of forming the precursor.
- 49. An oxidatively treated fuel product comprising a sulfur-containing fuel exposed to an aqueous solution of a compound of a metal selected from the group including alkali metals and alkaline earth metals to form a basic and distributed precursor whereby a major portion of the sulfur in the fuel, when the fuel is burned, will be trapped as a sulfate in the ash.
- 50. A fossil fuel treated by the process of any of claims 1, 7, 11, 16, 20-22, 26-39, 44 and 49.
- 51. A treated coal produced by first oxidizing a coal to introduce cationic hydrogen and thereafter exposing the coal to an aqueous salt selected from the group including an alkali metal and an alkaline-earth metal for a sufficient time period to substitute said aqueous salt for said cationic hydrogen.
- 52. A treated coal as in claim 51, wherein said coal is oxidized by first comminuting the coal and then treating the coal in a mixture of nitrogen dioxide dissolved in carbon tetrachloride at approximately ambient conditions for a period of time sufficient to introduce cationic hydrogen in place of at least 20% of the hydrogen initially present.
- 53. A treated coal as in claim 51, wherein the time period is at least 30 minutes.
- 54. A treated coal as in claim 51, wherein said aqueous salt is present at a concentration of about 0.1M.
- 55. A treated coal as in claim 51, wherein said time period is about 2 hours.
Parent Case Info
This is a continuation of application Ser. No. 259,736, filed May 1, 1981 now abandoned.
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
495062 |
Sep 1976 |
AUX |
2755487 |
Jun 1978 |
DEX |
Continuations (1)
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Number |
Date |
Country |
Parent |
259736 |
May 1981 |
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